Fig. 1: Optical configuration and light efficiency.
From: High-efficiency multi-scale holographic volumetric 3D printing with a phase light modulator
a Schematic of the optical configuration for HoloVAM using a PLM as a Spatial Light Modulator. An aspherical collimation lens (CL) collimates blue light from a laser diode coupled to a single-mode fiber (SMF). After the PLM, a Fourier lens (L1) is placed, with a spatial filter (SF) at the focal plane of L1 to remove undesired diffraction orders. A 4-f system (L2 and L3) conjugates the Fourier plane (CP*), which then serves as the printing region. A glass vial (GV) acts as the sample container and a rotation stage (RS) holds the sample container. An index matching bath (IMB) is used to minimize optical distortions caused by the curved walls of the cylindrical GV. b Illustration of PLM row of micro-mirror pixels in piston fashion displacement to impart phase delay. c Light efficiency comparison
